I have used this a couple of years back. Forgot it completely until it somehow showed up during a search. It was a bit short of features at that time and I moved on. But when we need a CMS which need not be updated as frequent as WordPress and still work well, MODX can be good.
They have drag and drop UI extension which works more or less similar like WordPress Blocks. It is a PHP script like WordPress. MODX has their own cloud hosted solution.
Nice to see MODX still hanging around. It is a fairly decent software. Their backend is very simple.
I wonder how the community support is. I haven't tried that part yet.